TehRaydarlover's AWD Lover

[TehRaydarlover]

Yeah, I'm curious to know if my rear diff has the welded cover or the snap ring cover. Mine is a '90 so who knows.

As far as the viscosity goes, I was shooting for 88k cst. I used this website:

http://scriptasylum.com/rc_speed/oil_mixer.html

which calculates that you need 75% 100k cst and 25% 60k cst.

I don't know if the volume that I put in it or the ratio was dead on but it is without a doubt stiffer than factory. Its a good and bad thing. You can tell when making tight turns into a parking spot the most. The drivetrain tightens up and the rear diff makes a slight rumble in that situation but its fine otherwise. I just take it easy when i'm parking honestly. It handles great in the snow and does some very interesting donuts in empty parking lots (in snow of course). Around corners you can whip the tail out by giving it gas and then it always wants to pull itself straight again.

That would have been really cool to get the info from a ZF employee, or ex employee. I've emailed them and called them a few times to try and get the info myself and they have no been willing to give it out. I'm probably on their shit-list.

If and when I do the next one I was thinking that I might just use slightly less volume but the same mix. If I recall, air-space in the V/C is key for the lock up characteristics as well as viscosity.

Yeah, I have no idea what diffs got a rebuildable rear VC. Both of the two I took apart we from '88 and one was and one was not

Good to hear it locks up well! How did you decide on 88K cs? I'm thinking I'm going to let it sit for a while and get all of the air up to the top then take a look at the expansion rate of the silicone and try and determine how much space I need to leave for expansion. I've got another VC cut open that I can measure the empty volume. Then just top off my filled VC and remove whatever I come up with for the expansion.

[Eskie]

Ah! I just re-read that you filled it and went back a page to check it out. Awesome!

Did you fill it all the way up to the fill plug or use a specific volume?

[Eskie]

Thanks! Yes this is the center VC, although if you look back at my rear diff rebuild the one of the two rear VC I used had a similar design from BMW, I resisted the urge to open it as it was the one I ended up using so I'm not sure what they used to seal it but I'm guessing some sort of o-ring.

Maybe if work slows down a lot and I finish my build I could make a few, but for now this is a one off.

Nice, yes I saw your thread when doing research for this project. How did you decide on the viscosity of the silicone fluid? There is a car show in Chicago that I go to every year, Windy City - Vintagefest. Its at the ZF plant, Talking with a guy who worked there he was going to try and get me the specs on the viscosity and volume of fluid in the VC. Unfortunately, he never followed through for me :( I ended up following you with the mix of 100,000 cs and 60,000 cs. From your experience it seems to work well

Ray

Yeah, I'm curious to know if my rear diff has the welded cover or the snap ring cover. Mine is a '90 so who knows.

As far as the viscosity goes, I was shooting for 88k cst. I used this website:

http://scriptasylum.com/rc_speed/oil_mixer.html

which calculates that you need 75% 100k cst and 25% 60k cst.

I don't know if the volume that I put in it or the ratio was dead on but it is without a doubt stiffer than factory. Its a good and bad thing. You can tell when making tight turns into a parking spot the most. The drivetrain tightens up and the rear diff makes a slight rumble in that situation but its fine otherwise. I just take it easy when i'm parking honestly. It handles great in the snow and does some very interesting donuts in empty parking lots (in snow of course). Around corners you can whip the tail out by giving it gas and then it always wants to pull itself straight again.

That would have been really cool to get the info from a ZF employee, or ex employee. I've emailed them and called them a few times to try and get the info myself and they have no been willing to give it out. I'm probably on their shit-list.

If and when I do the next one I was thinking that I might just use slightly less volume but the same mix. If I recall, air-space in the V/C is key for the lock up characteristics as well as viscosity.

[TehRaydarlover]

I added some more detail about filling the VC to my last post on the previous page.

Hi !! Great rebuild for your car !!I follow you

325ix my turbo breaking my two front differential

Remy

Thanks! Curious, what was the failure point in your two broken diffs? I'm guessing the spider gears, but maybe the crown gear?

Ray

Absolutely awesome work and engineering in regards to the rebuildable V/C. It is the center correct? Do you think you may be selling these rebuild housings in the future?

I've got a spare blown V/C that I've been toying around with the idea of doing this for a long time but haven't because I lack the skills and machines. I did however rebuild one a couple years ago but cutting it open, replacing the o-rings, refilling it and welding it back together. Been daily driving it in the winter ever since and still functions great. Heres the thread, maybe there is some info that can help: http://www.e30tech.com/forum/showthread.php?t=118249

Excited for more!

Thanks! Yes this is the center VC, although if you look back at my rear diff rebuild the one of the two rear VC I used had a similar design from BMW, I resisted the urge to open it as it was the one I ended up using so I'm not sure what they used to seal it but I'm guessing some sort of o-ring.

Maybe if work slows down a lot and I finish my build I could make a few, but for now this is a one off.

Nice, yes I saw your thread when doing research for this project. How did you decide on the viscosity of the silicone fluid? There is a car show in Chicago that I go to every year, Windy City - Vintagefest. Its at the ZF plant, Talking with a guy who worked there he was going to try and get me the specs on the viscosity and volume of fluid in the VC. Unfortunately, he never followed through for me :( I ended up following you with the mix of 100,000 cs and 60,000 cs. From your experience it seems to work well

Ray

[Eskie]

awesom

Absolutely awesome work and engineering in regards to the rebuildable V/C. It is the center correct? Do you think you may be selling these rebuild housings in the future?

I've got a spare blown V/C that I've been toying around with the idea of doing this for a long time but haven't because I lack the skills and machines. I did however rebuild one a couple years ago but cutting it open, replacing the o-rings, refilling it and welding it back together. Been daily driving it in the winter ever since and still functions great. Heres the thread, maybe there is some info that can help: http://www.e30tech.com/forum/showthread.php?t=118249

Excited for more!

[FAROYE.MOTORSPORT]

Hi !! Great rebuild for your car !!I follow you

325ix my turbo breaking my two front differential

Remy

[TehRaydarlover]

Custom O-ring made


Pressure test was a success! I'm not sure how much pressure I tested it at but shop pressure is 125psi. I just cracked the valve for a second and let it sit overnight. Still was pressurized in the morning. :D


I filled the VC last week after work. Ended up using roughly 3 parts 100,000 cs and one part 60,000 cs silicone fluid. Unfortunately, I only have the one picture, my hands got covered with silicone haha. My method was to add silicone slowly as I added plates to make sure every plate had a film. I used a hand press to push the plates down and squeeze out the silicone as I added more plates. I kept having an issue where when I pressed the plates down the center sleeve would rise up with the silicone, disengaging the first few plates in the bottom of the VC. Had to be very careful to push it back down with out turning it and having the splines get misaligned. With all the plates and spacer rings installed I put the cover on and installed the snap ring. I made sure it wasn't over filled by leaving the fill plug out and removing any excess silicone. Some thread sealant on the pipe plug and its all ready to go. I'm going to try and reassemble the transfer case this weekend with all new bearings, seals, gaskets, and of course the "new and improved" VC :D

[TehRaydarlover]

I'll try to use them to their full potential haha!

[burkey001]

hope you enjoy my ID1000 fuel injectors via ebay

[TehRaydarlover]

Thanks guys!

I added a small anti-rotation pin to the cover. There shouldn't a lot of torque put on the cover with in service but just in case, I wanted to make sure it couldn't go anywhere.

[Nisse Järnet]

Nice work!

[stonea]

Man its been a while since I've seen this thread. Great work, we need more ix love on the forums.

[TehRaydarlover]

Fill hole has been drilled, reamed, and tapped for a 3/8 NPT plug. I also made the custom 0.070" o-ring. Hopefully next week I can pressure test everything and put it together for real.

[TehRaydarlover]

oh man was wondering what was going on with your build....that rust sucks! I wish we didn't have to drive on salted roads, but thats just the name of the game.

I just coated the undercarriage of my car w/ Formula 3000. hoping it will help even just a little from this winter.

Yeah it was pretty shocking and depressing when I stripped everything down, but now I've got all the panels to make it new again. I'm going to strip all of the undercoating off and paint everything in this industrial epoxy we use on salt water pumps at work. should hold up well haha.

Great build thread, loving the engineering work

Thanks!

[Julien]

Great build thread, loving the engineering work